Process and machine for making bags



July 19, 1938.

G. W. POPPE PROCESS AND MACHINE FOR MAKING BAGS Filed July 31, 195e 4Sheets-Sheet 1 INVENTOR Gia/@af 14./ PoP/Pf ATTORNEY July. 19, l1938. G.w. POPPE PRocEss'KND MACHINE FOR MAKING BAGS' Filed July 31, 1956 4Sheets-Sheet 2 l ATTORNEY G. w. PoPPE PRocEss'AND MACHINE FOR MAKINGBAGS July 19, 1938.

Filed July 3l, 1956 4 Sheets-Sheet 3 INVENTOR 65e/Q65 MPa/QPF;

July 19, Y1938. G. w.` POPPE v Pnocss ANDMACHINE Fon MAKING BAGS -FiledJuly 51, 195e 4 Sheets-Sheet 4 INVEN-roR G50/eef ll/4 PoP/f ATTORNEYPatented July 19, 193s .UNITEDfs-TATr-:s-

PATENT fol-#Fics PROCESS' AND MACgNE FOR Application July 31, 193s,serial No. sasso claims. (ci. ca -1s) 'I'his invention relates tc-aprocess Vantimachine for making paper bags. v

' In my Reissue Patent-19,921' granted April 7,

i936, I have disclosed ay method and apparatus 5 for making bags inwhich a web of paper is continuously fedthrough themachine and cuts aremade at 4intervals in the web which cuts determin the sides of theclosing iiap in the iinished bag. -The web is folded to form abag tubewhich is then severed along lines which meet both ends 4 of the cuts.The machine disclosedin said reissue patent is provided withv severingmechanism in the form ofA a striker baro' bars which cut off bag lengthsfrom the continuously moving tube, the cutting being effected throughthe lmedium o f serrated edge knives. s y In making bags accordingtothis method, there is no waste of paper and furthermore where thelongitudinal cuts are at aslight angle gussets are. formed at the bottomof a bag tube section.' The bottom fold may then-include but one bagwall and therefore the bag bottom may be made smaller than-the closingflap. This results in`` saving of paper over that necessary to be usedwhere both bag walls are included within the bottom fold. v

Ithas been proposed to make a' bag `by preli'minarily perforating the.web along' transverse and general longitudinal lines which determinethe size of the closing flap to lbe produced, then `folding the web toform a tube and finally completeiy severing the tube into' bag lengthsalong the lines of the perforations. Such a method .is described in thepatent to Potdevin'1,941 ,272, December 26, 1933. The patenteerecognizes the desirability of having a-small bottom relative to j thelength of the closing ilap and in' order to produce such small bottom,-he contemplates cutting oil a portion of a tube length before the bag isbottomed. "I'hiscut-ofl portion however,

constitutes waste. i f' It has also been proposedto do away entirely,with the striker bar in machines of this general character althoughutilizing the Potdevin method of. yiirstperi'orating or weakening theweb along transverse and general longitudinal lines which lines oi!Aweakening determine the size `of the closing flap to be produced. Theweb is then folded and pasted in the usual way and the severance ofindividual bag tube lengths from the continuously advancingtubeiseffected as follows: The folded tubepasses iromthe-usual feed rolls tothe bottom forming cylinder which cylinder at a higher peripheral speedthan the` Aieed rollers, and as soon as the bag bottom enters ingdrawings in which:

closing the bottom of the bag tube sectionto form l at,

the usual clamp in said bottom forming cylinder, a bag tube length issnapped od from the 'main bag tube along vthe weakened lines. Thetiming.

is such that the weakened or perforated Iportions are just past the feedrollers when the'bottoming 5 cylinder takes hold and severs the bag tubealong the lines of weakening. Howeven in employing 4 this process it isnecessary that the bottom of the bag be folded in such a. manner as toinclude both walls within the line `of fold. In other words, m bothwalls of the bag tube must be included within the 'clamp on the bottomforming cylinder. This necessitates the making of a bottom. which islargerthan the closing flap and not only is wasteful of paper, butproduces a bag unsightly in ap- 15 'pearance, especially when theclosing iiap is oi substantial length as for instance, two inches,onmore. e

One of the objects of the present invention is x the'production of a bagby the general process 20 above described. but without the necessity forin;

cludingboth walls of the bag ytube within the bot- .proved method whilemaintaining high speed'oi' production. ,f

-The invention will'be vbetter understood by reference-to the followingdescription and claims when taken in connection with the 4accompany-4Figure 1 is a longitudinalsection of avbag mal chine adaptedto make bagsaccording tomy improved process.

Figure 2 is a plan view more or less diagrammatic showing the essentialstepsv of the process. Figure3 is a top plan View of a portion of therear of the machine and-illustrating the manner in which the web isvcut,i l

Figure 4 is a front view of the knives and cooperating cylinderformaking cuts. in the web whichdetermine the side edges of the closingilap.-

. Figure 5 isA a. sectional view on an'enlarged 5ol scale of vthe frontportion of the machine shownl in Figure l and illustrating how a bagtube section is severed from the main bag tube prior to a nished. ba'g.

Figure 6-is a perspective view ofthe rear portion of the machine andbetter illustrates the driving connections.

Figure 7 is a side elevation of a portion of the front of the machineshowing the change gearing.

Figure 8 is a bag tube section prior toclosing the' bottom thereof; and

Figure 9 is a nished bag.

Referring to Figure 1 vof the drawings, 2 indicates one of the sideframes of the machine which frames support the operating mechanism. Aroll of paper 4 is mounted on a shaft 5 supported from the machineframe. A web of paper 6 is drawn from the roll 4 and passes under andover idler rollers l and around a driven roller 8 and A about an idlerI0. At this point a line of paste of the web. Between the ends of saidperforations but offset therefrom the web is also perforated along theline I8, Figure 2. The perforations I1 are made by two aligned knives20, the edges of which are discontinuous or serrated. 'I'he line ofperforation I8 is made by a similarly constructed knife lI9. Both oftheknives 20 and the knife I9 are carried by a cylinder 2l which ispositively ldriven as will be later described.

The knives 20 are circumferentially offset from the knife I9, the lattercoming first into operation as the web is advanced through the machine.

After the web has passed over the rubber roller I6 and has beenperforated or weakened along the lines I l, and along the line I8, itpresents the appearance shown at section A, Figure 2. It then passesunder an idler roller 22 and over a steel roller 23 where it receivesthe cuts 24 which cuts are diagonal in respect of the longitudinal lineof the web. These cuts join the inner ends of the perforations I1 withthe. outer ends of the perforations I8 as clearly shown in Figure 2,section B. After receiving the cuts 24, the web passes under a roller`26supported by an arm 21 carried by a shaft 28 suitably supported by aframe 29, the latter carried by the framework of the machine. 'I'heframe 29 carries at its lower portion the usual former 30 under whichthe web passes and about which it is wrapped to form a bag tube in theusual and well known manner common tvo bag machines. The folded tube issubjected to the action of rollers 3| which'tend to smooth down theoverlapped portions of the web and aid in drawing the tube more tightlyabout the former 30, asis likewise customary in machines of thischaracter. The tube. then passes between feed rollers 32 which areposibag section as shown at Figure 2, section C, vand in Figure 8. Thecuts 24 will determine the side edges of the closing flap and also theside edges of the gussets which are formed at the bottom of a bag tubesection.

The cuts 24 are produced by two knife edges 34 each supported in a block35, Figures l, 3, and 6, said blocks being carried on a shaft 36 whichis positively driven as will be later described. The blocks 35 areadjustable along the shaft 36 and are so constructed that they may carrya knife at diametrically opposite portions thereof. A pair of knives areused in each block when a bag or one-half the length of the oneillustrated, is to be made.

These knives 34 may be of the character shown in Figures 6, 7, and 8 ofmy Reissue Patent 19,921 .and described in detail therein. Instead ofhaving a continuous edge, however, as shown and described inv saidreissue patent, these knives may have their edges interrupted as shownand described in my Patent 2,030,118 (see Figures 3 and 4).

Preferably where the closing flap of the bag is of medium length, notexceeding two inches, for example, the continuous edge knife would beused. Where the closing flap is longer it may be desirable to use thetype of knife edge illustrated in said Patent 2,030,118 for'the reasonsstated in said patent. l

In the Potdevin Patent 1,941,272 previously referred to, the side edgesof the closing flap are formed by serrated edge knives 5 and 1 shown inFigure 2 of said patent. [It is of course obvious that such perforatorsas described in said Potdevin patent may be used in the present case.However, there are several objections to perforating the web in themanner there illustrated. 'I'he serrated edge knives I9 and 20 shown inFigure 3 of the present application and corresponding to the knives 4,8, and 8 of the Potdevin patent must cooperate with a roller of yieldingmaterial, such as rubber. I have found in practice that when serratededge cutters are use d in connection' with such rubber roller todetermine the side edges of the closing flap. lvery shortly grooves areformed in the rubber roller and that then the perforations are notsumciently deep to enable the bag sections to be properly severed fromthe main tube. Itv is/then necessary to substitute a new rollercorresponding to the roller 3, Figure 2 of the Potdevin patent, whensuc'h method is used.

With my improved method and apparatus wherein the preliminary cutting ofthe web is performed in two stages, not only are the objectionablegrooves eliminated, but the side edges of y the closing flap may be madesmoother.

In the present machine-the roller 23 is of steel and therefore issubject to very slight wear.

After the tube has been folded as described, and the folded tube hasprogressed to the position shown at section C, Figure 2, the nextoperation consists in completely severing a pag tube section from themain bag tubeto produce separate bag sections which may be suitablybottomed to produce a complete bag.

In the present invention a bag tube section is severed from the main bagtube by means shown more clearly in Figure 5.

A shaft 38 is carried by a frame 39 which is `supported on the mainframe of the machine.

By means which will be described more in detail hereinafter, the shaft38 is positively driven. A

sector block 40 is carried by said shaft and is cir- 'I6 cumferentiallyadjustable thereon. A pinch bar 42 may -be mounted at diametricallyopposite positions on said sector block 40 although but one such bar isshown in Figure 5 for making the bag length illustrated. l

The rconnections are such that the surface speed of the pinch bar 42 isgreater than the surface speed of the feed rollers 32. The timing issuch that the bag tube is pinched 'between the pinch bar 42 and acooperating roller 44 just after the cuts or weakened portions of thebag tube pass the feed rollers 32. The pinch bar, therefore, by reasonof its greater surface speed operates to snap a bag tube section fromthe main tube alongthe lines of weakened portions thereof while the maintube is being held by the feed rollers 32. Figure 5 shows clearly a bagtube section vas having been separated from the main bag tube and thisis also shown in Figure 2, section D. The

severed bag tube section is then passed to the bottoming mechanism whichpastes and folds the bottom of the bag, the section being supported inits travel after leaving the pinch bar mechanism by a transverselyextending plate-45. The frame 39 is adjustable along-the machine bed toproperly position the pinch bar mechanism for bags of different lengths.

The bottoming 4mechanism is generally of well I known construction. butiniorder to make the disclosure complete, said mechanism will be brieflydescribed.

A cylinder 46 is supported on a shaft 41, said cylinder carrying a pastebar 48 running longitudinally of the cylinder. It is secured by screwsto a bar 49 as is usual in machines of this type. The bar 49 is moved inand out a short distance by a cam shown in dotted lines at 50, Figure 5,said cam engaging a roller 5| carried by a bell crank 52 mounted onshaft 53 supported in the cylinder 46.V The other end of the bell crankengages a roller 54 carried by the bar 49. Thisv bar is normally urgedin a radial direction to project the paste bar beyond the circumferenceof the cylinder 46, but the action of this spring is resisted by the cam50 which is of such contour that the paste bar is withdrawn tosubstantial coincidence with the surface of the cylinder 46 as the pastebar approaches the positionto apply the paste to the bag tube, thiswithdrawal being necessary to prevent interference'of the paste bar withthe lower cylinder. However, after the cylinder 46 has rotatedsufiiciently to take the paste bar out of the zone of the paper, the campermits the-'springs 56 to project the paste bar to a position tocontact with the paste applying roller 56 rotatable in a recess in apaste pot 59. In the present case the cylinder 46 is arranged to supporttwo paste bar mechanisms, both however-l operating as above described.

The cylinder 46 also carries a tucker blade 60 and may carry anothersuch blade at a diametrically opposite position. For makingthe length of:bag shown, however, but one tucker bladeis used. This blade cooperateswith a clamp 6I in the bottoming cylinder 62.,` This cylinder may carryfour clamparall' four of which may be used for makinga short bag. If thebag length ex-- to it a spring 69 which causes the clamp to close whenpermitted by the cam` 61. ,n

The-complete severance of a/bag tube section from the main bag tube bythe pinch bar 42 prior to bottoming a bag tube section, is an importantfeature of the present invention and enables a bag to be produced havinga small bottomwithout waste `of paper. The importance of this featurewill be better understood by reference toA methods heretofore used forcompletely severing a bag tube section from the main tube along lines ofperforations or weakened portions previously made in a web or tube. Inaccordance with methhigher peripheral speed than the feed rollers and ithas been heretofore proposed to. pass the weakened bag tube directlyfrom the feed rollersto the clamp 'cylinder which did the severing. Itis necessary, however. that -both walls of the bag tube be held duringsuch severance and therefore' when the clamp cylinder is used to snapof! a bag tube section, itis necessary that both walls of the tube betucked into the clamp in order that such severance may be possible.

By the method of the present invention, however, the severance of a bagtube' section from the main bag tube is brought about by the pinch barmechanism and not by the clamp cylinder.

` During the action of the pinch bar mechanism,

the pinch bar 42 engages the bag tube in such a position as to alwayspinch both walls of the tube pinch bar is about to let go of the severedbag tube section, the tucker blade 60 begins to push the bottom portion,of the bag into the clamp 6i but such folding includes but one bagwall. In other words the line of fold is along the line a-a, Figure 8.Consequently the bag made according to my improved method contains amuch smaller bottom than isy possible with the method previouslyreferred to. The saving of` paper amounts to approximately '1%. 'I'hisbecomes an extremely important item when it is rememmay be driven in-any suitable way either directly by a motor or by overhead shaftlng inwhich case the shaft. 1I would'be provided with a pulley on the endopposite to that shown in Figure 1. A bevelled gear 12 carried by saidshaft 1| meshes with a similar gear 13 on a shaft -14 running to atransmission casing 15 (see also Figure 6).' A stud shaft projects fromthe lower portion of said casing and is 'provided with a bevelled gear16 meshing with a similar gear 11 on fa shaft 19,

lthe latter shaft carrying a sprocket '19. A

sprocket chain conveys motion from the shaft 1l to the mechanism in therear of the machine. The sprocket chain passes about said sprocket -19and about a sprocket carried by a `shaft 09 whereby the latter shaft ispositively driven. The sprocket chain is suitably guided overintermeditov ate idlersla and 99h, the latter being mounted 75 on an armwhereby the tension of the sprocket chainmay be adjusted.

The shaft 80 carries thereon a small gear 8| and a larger gear v82. Thegear 8| meshes with an idler gear 83 carried by stud shaft (Figure 6),said gear 83 in turn meshing with a gear 84 on the shaft carrying theroller 8 whereby said roller is positively driven and aids the feedrollers 32 in pulling the web through the machine.V

The larger gear 82 carried by the shaft 80 meshes with an adjustableidler gear 85 carried by a stud shaft 86, said gear 85 meshing in turnwith a gear 81 secured to the shaft 88 upon which is mounted the roller2| supporting the cutters I9 and 20. The stud shaft 86 and the shaft 8,8are both adjustable for a purpose which will later be explained.

The shaft 36 carrying the knives 34 derives its motion from the gear 81through means of gears 89, 90, 9|, and 92, the latter gear being securedto the shaft 36.

By the means above described, the shaft carrying the roller 8. the shaft88 carrying the cutters I9 and 20, and the shaft 36 are all positivelydriven in the proper direction. The various shafts and lgears aremountedin an upper frame' which is adjustable along the machine bed inorder to permit bags of different lengths to be conveniently made. Theadjustment is` effected by means of bolts 93 operating in T-slots 94shown in dotted lines, Figure l.

The mechanism at the front of the machine also derives its motion fromthe shaft 1| and for this purpose said shaft carries a gear 96Lshown indotted lines, Figure 1, which gear meshes with a gear 98 carried byshaft 91 on which the clamp cylinder 62.is mounted.

The feed rollers 32 are driven from the shaft 91 .through change gearmechanism. For this purpose the shaft 91 carries a gear 99 (see Figure'1) somewhat smaller than the gear 98. Said gear 99 'meshes with a gear|00 carried by a stud shaft |0I. The gear |00 in turn engages a gear |02on shaft |03, which is the lower feed roller shaft. Gear |02 meshes withgear |04 on the upper feed roller shaft |05. The vchange gearing abovedescribed is provided in order that the feed rollers may be driven atdifferent peripheral speeds in relation to the clamp cylinder 62. Thegear 99 mounted on the shaft 91 may I be removed and agear containing adifferent number of teeth substituted to change the ratio oftransmission between the clamp cylinder and the feed rollers. To thisend also the stud shaft |0I is carried by a bracket |06 which pivotsabout the shaft |03 and may be secured in its dierent adjusted positionsalong a slot |08.in the bracket. The bracket |06 is also provided with aslot |09 along which the stud shaft IOI may be adjusted and properlyclamped in lts various adjusted positions.

The pinch bar mechanism is driven directly from the clamp cylinder 62and for this purpose a pinion I|2 engages the gear 98 and also the gear|I4 carried by a shaft H6 which supports the roller 44. The pinch barshaft 38 carries a gear I|8 meshing with the gear II4. By this train ofgears the pinch bar is driven at the same peripheral speed as the clampcylinder and both are always driven at a higher peripheral speed thanthe feed rollers.

The clamp cylinder is geared to the cylinder 46 carrying the tuckerblade 60 in a two to one ratio and this ratio also exists between theclamp cylinder andthe pinch bar shaft 36. As illustrated in the drawingsand using one pinch bar 42 and one tucker blade 60, two complete bagswould be made at each single rotation of the clamp cylinder 62. Thepinch bar however, and the cylinder 46 make two rotations as do likewisethe cylinder 2| and the knife shaft 36..

It will be recalled that the block 35 may have a knife 34 atdiametrically opposite ends thereof so that with each rotation of theshaft 36 two pairs of slits would be made in the web. Like- Wise thecylinder 2| instead of having a single pair of cutters I9 and a singlecutter 20 may have duplicate sets of these at diametrically oppositepositions thereby making two sets of perforations for each singlerotation of the roller 2|. It will be obvious, however, that with thisarrangement, the bag length would be only onehalf of that shown in thedrawings. It would also be necessary to use two pinch bars 42 and twotucker blades 60 and also two paste bars. Thelengthof such a bag wouldnecessarily have to be shorter than the circumferential distance betweentwo adjacent clamps on the cylinder 62. InA making 'the shorter bag allfour clamps would be used.

If the bag length is longer than thev circumferential distance betweentwo adjacent clamps on the cylinder 62, which is the condition actuallyshown in the drawings, a single tucker blade 60 is used which cooperateswith'every other clamp 6| on the cylinder '672. To make a bag ofdifferent length than the one shown in the drawings, it is necessary tochange the ratio of drive between the clamp cylinder and the feedrollers 32 and this change is made by taking off the gear 99, Figure 7,and substituting a gear having a different number of teeth. It is notnecessary in such case, however, to make any Vchange in the pinch bar'mechanism or the tucker blade cylinder. It is necessary, however, tomake a change in the rear portion of the machine because the shafts 88and 36 must be driven once for each bag or each two bags and hence theshaft carrying the idler gear 9| is made adjustable so that a differentsize gear may be used for a different bag length. This is likewise trueof the shaft 60 and the shaft 86 carrying the idler 85. In the making ofa longer bar than theone shown, the

cylinder 2| would have tobe replaced by a cylo inder of larger diameters6 that during one rotation of said cylinder, the knives I9 and 20 wouldmake their cuts at the proper distance apart to determine the longer bagtube section.v

The knives 34 must also be changed and knives of the proper radiusofcurvature substituted.

What I claim is:

1. The method of making bags without waste of material which consists inproducing generally longitudinal and transverse cuts or weakened linesat regular intervals in a continuously advancing web, which cuts do notcompletely sever the web, so folding the web as to form a bag tubehaving upper and lower walls with said cuts defining a bag tube section,producing an acceleration in the direction of advance of the web ofsuccessive bag sections to completely sever a section from the bag tubealong lines as defined by said cuts to provide a iiap at each end of abag tube section, and thereafter folding one of said flaps 'over thebottom of a bag tube section to close the same, said fold including butone bag wall.

2. In a bag machine, the combination with a former about which a web ofpaper is wrapped to aisance form a bag tube, and feed rollers foradvancing the tube; of means for perforating the web prior to foldingthereof valong lines which delizie a bag tube section vafter the web isfolded, pinch bar mechanism operated at a greater peripheral speed thanthe feed rollers and acting to separate successive bag sections from themain tube, and

means for subsequently bottoming the bag tube sections, saidpinchbarfmechanism acting to feed a severed bag section directly to thebottom- 4ing mechanism.

3. In a bag machine, the combination with a n former about which a webof paper is wrapped to form a bag tube and feed rollers for advancingthe tube; of means for perforating' the vweb prior to folding, alonglines which define a bag tube section after the web is folded, pinch barmechanism operating ata greater peripheral speed than the feed rollersand acting to separate successive bag Asections from the main tube, andbottoming means for folding the bottom of each bag section along a linewhich includes one wall only of a bag tube section, said pinch barmechanism acti ing tor feed a severed bag section directly to thebottoming mechanism.

4. The method of making bags without waste of material which consists inproducing two series of cuts in a continuously advancing web, the twoseries being in transverse alignment `but separated transversely,forxning a third series of transverse cuts located between thelnner endsof the two series of cuts but off-set therefrom in a longitudinaldirection of the web, thereafter making cuts which join the outer endsof the third one bag wall.

series of cuts with the inner ends of the ilrst two series of cuts,which latter cuts do not completely 5. The method of making a bag from abag tube section, said section having a bottom flap and a top closingflap which method consists in producing two series of interrupted cutsin a continuously advancing web, the two series being in transversealignment but separated transversely, forming a third series ofinterrupted transverse cults located between the inner ends of the twoseries of cuts but offset therefrom in a longitudinal direction of theweb, connecting the outer ends of the third series of cuts with theinner ends of the rst two series by continuous cuts which' latter cutsdefine the side edges of the closing flap of the finished bag, foldingthe web i.

to form a bag tube, completely severing the tube into a bag section asdefined by said cuts to produce a flap at each end of a bag tube sectionand thereafter folding one of said flaps over the bottom of the bag tubesection to' close the same, said fold including but one bag wall.

GEORGE W. POPPE.

